Terry,
You need power tube data sheets? Have I got a site for you, OM.
Here's a large collection of original sheets and operating parameters, many from Eimac. Click on either triode or tetrode at the top of the home page and go to town.
Yes, Bill's correct... an 8877 is really a 3CX1500A7. A Hi-mu triode designed for GG linear service. But "8877" is the common designation. The 4CX-1500B is also a very clean tetrode for grid driven linear service too. In big demand.
http://www.g8wrb.org/tetrodes.shtml [It is listed here as "3CX1500A7"]
73,
T